Abstract
Data are commonly exchanged between an in-vehicle unit and the external world today, and there are demands for more stable and efficient mobile data communication. This paper proposes a system for controlling data communication in reference to data on the radio wave environment. The basic concept of the overall system, which focuses on field strength among several indices of the quality of the environment, is described first. An explanation is then given of an evaluation system and a test vehicle that have been developed for the purpose of measuring and evaluating field strength during driving. The test results measured with this experimental system are discussed along with several issues for future work.